Automated system for controlling the blood glucose level of a patient

An automated system of regulation of a patient's blood sugar, comprising:

• a blood sugar sensor;
• an insulin injection device;
• and
• a processing and control unit capable of predicting a future evolution of the patient's blood sugar from a physiological model and of controlling the insulin injection device by taking the prediction into account,
• wherein:
• the physiological model comprises a differential equation system describing a time variation of a plurality of state variables;
• and
• the processing and control unit is capable of implementing a step of automatic calibration of the physiological model comprising:
• a) a step of estimation of parameters of the differential equation system by minimization of a quantity representative of an error, during a past observation period, between the patient's blood sugar as estimated based on the physiological model and the patient's blood sugar as measured by the sensor;
• and
• b) a step of estimation of initial values of the state variables by minimization of said quantity representative of an error, during a past observation period, between the patient's blood sugar as estimated based on the physiological model and the patient's blood sugar as measured by the sensor;
• wherein said quantity is representative of the area between a first curve ĝ representative of the time variation of the patient's blood sugar as estimated based on the model over the observation period, and a second curve g representative of the time variation of the patient's blood sugar as measured by the sensor over the observation period;
• and wherein, at step a), the parameters are determined using an algorithm for solving problems of parameter optimization by minimization of a cost function, and, at step b), the initial values of the state variables are determined using an algorithm for solving problems of parameter optimization by minimization of a cost function.